Problem: Is ${549003}$ divisible by $4$ ?
Solution: A number is divisible by $4$ if the last two digits are divisible by $4$ . [ Why? We can rewrite the number as a multiple of $100$ plus the last two digits: $ \gray{5490} {03} = \gray{5490} \gray{00} + {03} $ Because $549000$ is a multiple of $100$ , it is also a multiple of $4$ So as long as the value of the last two digits, ${3}$ , is divisible by $4$ , the original number must also be divisible by $4$ Is the value of the last two digits, $3$ , divisible by $4$ No, $3$ is not divisible by $4$, so $549003$ is also not divisible by $4$.